Iran’s Revolutionary Guards said on Tuesday it had captured a ‌US uncrewed submarine at the entrance to the Strait of Hormuz, offering a rare glimpse into how underwater drones are being used in military operations.

Iranian state media said the vessel was a Dive-LD, a large autonomous underwater vehicle built by California defence firm Anduril. The 5.8-metre (19-foot) submersible can carry out missions including mine countermeasures, seabed mapping, intelligence gathering ⁠and the inspection of underwater infrastructure such as cables and pipelines, the company has said.

“We trapped ‌one of the most modern, intelligent and unmanned submarines of the terrorist American army at the entrance to the Strait of Hormuz. This ‌submersible is equipped with the latest technologies,” the Revolutionary Guards Navy said in ⁠a statement carried by ⁠Iranian state media.

In response, a Pentagon spokesperson said an underwater drone had “malfunctioned more than a day ago”.

“It ‌was surveying regional waters in support of ongoing operations. The defective drone was an older model that neither collected sensitive data ‌nor ‌carried any classified sonar or radar equipment,” the spokesperson said.

Reuters could not independently verify ‌Iran’s claims and the Pentagon did not address them in its statement. Anduril did not respond ⁠to a request for comment.